From patchwork Wed Sep 12 18:14:02 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cyril Chemparathy X-Patchwork-Id: 1445991 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (unknown [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id E9ACA3FE79 for ; Wed, 12 Sep 2012 18:31:51 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TBrS1-0001nR-VT; Wed, 12 Sep 2012 18:14:14 +0000 Received: from devils.ext.ti.com ([198.47.26.153]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TBrRy-0001mh-2Q for linux-arm-kernel@lists.infradead.org; Wed, 12 Sep 2012 18:14:12 +0000 Received: from dlelxv30.itg.ti.com ([172.17.2.17]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id q8CIE9uc001435; Wed, 12 Sep 2012 13:14:09 -0500 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dlelxv30.itg.ti.com (8.13.8/8.13.8) with ESMTP id q8CIE9MT002571; Wed, 12 Sep 2012 13:14:09 -0500 Received: from dlelxv22.itg.ti.com (172.17.1.197) by dfle72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.1.323.3; Wed, 12 Sep 2012 13:14:08 -0500 Received: from ares-ubuntu.am.dhcp.ti.com (ares-ubuntu.am.dhcp.ti.com [158.218.103.17]) by dlelxv22.itg.ti.com (8.13.8/8.13.8) with ESMTP id q8CIE8Qk004097; Wed, 12 Sep 2012 13:14:08 -0500 Received: from a0875269 by ares-ubuntu.am.dhcp.ti.com with local (Exim 4.76) (envelope-from ) id 1TBrRw-0002b8-Ag; Wed, 12 Sep 2012 14:14:08 -0400 From: Cyril Chemparathy To: , , Subject: [PATCH] davinci: check for presence of channel controller on slot alloc Date: Wed, 12 Sep 2012 14:14:02 -0400 Message-ID: <1347473642-9948-1-git-send-email-cyril@ti.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -7.3 (-------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-7.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [198.47.26.153 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: khilman@ti.com, nsekhar@ti.com, Cyril Chemparathy X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org This patch adds a check for the presence of the channel controller when trying to allocate a slot. Without this fix, the kernel panics with a NULL pointer dereference when the dma-engine drivers are probed. Signed-off-by: Cyril Chemparathy --- arch/arm/mach-davinci/dma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/mach-davinci/dma.c b/arch/arm/mach-davinci/dma.c index a685e97..2fee31e 100644 --- a/arch/arm/mach-davinci/dma.c +++ b/arch/arm/mach-davinci/dma.c @@ -743,6 +743,9 @@ EXPORT_SYMBOL(edma_free_channel); */ int edma_alloc_slot(unsigned ctlr, int slot) { + if (!edma_cc[ctlr]) + return -ENODEV; + if (slot >= 0) slot = EDMA_CHAN_SLOT(slot);